Radiovision and telecinematography



Ma 21, 1929. E. *BELIN I RADIOVISION AND TELECINEMATOGRAPHY Filed ,Dec11. 1925 Patented May 21, 1929.

v UNITED STATES nnouaap imam, or rams, macs;

CRADIQVISION AN D TELECIN Application filed December 11, 1985, SerialNo. 74,879, and in France December 16, 1924.

In specification of U. S. Patent N 0 1,670,- 795, May 22, 1928, aprocess of tclevlslon was described. This invention relates to a morenearly defined method and apparatus. In order to shorten the descriptionthe mventlon will be described with reference to said speciprecedingspecification although sufficient in some cases, cannot be considered asentirely satisfacto asthe real optical image is notconstitute d in aplane when the seeing station is directed on a landscapewhere'successive 2 planes come into consideration.

Fig. 1 is a diagrammatic plan view of the invention;'

Fig. 2 is a diagrammatic plan view of the invention showin the beams asthey are reflected onto the p otosensitive elements; and

Figs. 3 and 4 are diagrammatic plan views of modified forms of theinvention.

, In order to produce an optical ima one plane, a lens arrangement shownin ure 1 is employed.

The lens 0 of very short focal length and having as large an aperture aspomible gives at A B close to its rear face a very bright and very smallimage of the object A, B. In the plane of this ima e is the axis 3 ofoscillation of the lowsispee mirror M The reflected beam is immediatelyreceived by the second lens 0 of lgreater focal lengththan the lens 0prefera 1y a microsco ic lens.

As the mirror M oscil ates about its'axis, Y, it will reflect all thediverging rays of $110- cessive vertical lines on the picture to themirror M By converging their beams it will suflice to place a mirror M(of high speed) having an axis s-z perpendicular to the plane inquestion for satisfactory conditions to be obtained and will suflice'however small it may be to transmit all the rays reflected by mirror Monto a photo-sensitive element 'uated in paral el planes are used.Mirror situated in the system 0,. 4 7

This photo-sensitive'element will therefore be explored by the whole oftherealv optical image and under identical conditionswhata ever may bethe rays question: r

With a system: Q Jfo'rmed' as a co 7 pound microscope, the emergent beamwill have its plane of the axis 3/ and of the 66 point of convergencevery near'the mirror M,

which may also be of small dimensions; The mirrors M M may of coursebeinverted.

An arrangemcntof this type has been made in which the larger mirror towhich only relatively slow displacements may be given is situated inrear of sighting lens. 50' placed it intercepts all the emergent rayswhich is not possi le with a very small mirror which has to move atgreat speeds. Inthe new arangement however thequickly moving mirror canbe made of dimensions so small as to be displaceableby mechanical-means.

Referring to Figure 2, two mirrors M M, having mutuall perpendicularaxes 31-4 sit- M is situated in rear of the lens 0 and intercepts theemergent beam near-t'othis lens'u' being the point at which the wouldotherwise be formed. The mirror which oscillates about the axis 3/ willcause mirror M to be swept by the beam. This sweeping action will take.place slowly for example 10-16 times er second.

During eac sweep, the mirror M, which os- -cillates about its axis 2will reflect the beam portion reflected by M which intersects itmomentarily, so that durin one oscillation of mirror M the whole of tportion pass over the hole in a diaphragm D behind which is aphoto-sensitive element S.

The distance of S from'the axis of mirror M is such that the sum gz+zS=M u; the image at S will therefore beas clear as itwas -31; a).

If therefore -M occupies a number of successive positions during 1/2oscillations of M suflicient to cover the width of M, (which shouldbesuflicient to embrace the reflected beam), the whole emergent beamwill have been explored by the element S. Inpractice these movementsarecontinuous and explora tions takes place by a' sort of sinuosity andnot by regularly spaced straight lines. 7

7 It will be understood however that this width of mirror M is verysmall, thus the mass of the mirror is very small; owing to thisarrangement both mirrors M and M can be driven mechanically inspiteofthe fact that the speed of mirror M is hi h.

For. the oscillating control 0 one of the analyzer mirrors at thetransmission end there may therefore be substituted a mechanical drivewhich will evidently consitute a simplification.

As in the former specification a photosensitive element whose resistancevaries continuously may be employed for imposin in a radio-electricemission of any system, ifierences of intensity, which so as not to beproduced in the oscillating form (vibratory or periodical) necessitatedby the vlbrations of a microphone (for in this case there is novibrating element) produce variation effects capable of'being quicklyreceived on arrival. It is clear that any amplifying means may moreoverbe interposed between this element and the emission. I

The receiving station should produce or project the image under the eyeof a spec-. tator; this will be called the projecting station. It mustof course comprise: 1. Suitable receiving means, for collecting theemisslons of the transmitting system controlled by the seeing post;nothing need be specified as regards this receiving station.

2. A system capable of translating the variations of emissions collectedinto variations of luminous intensities and this must take place inaccord with the variations of luminous in tensitly of the object.

istributing means which correspond -to the exploration means fortransmission,

and I 4. A projector means which ensure the visibility upon a screenaccording tothe local necessities for one or a number of spectators.

In the prior specification there were described means for translatingvariations of the waves received into variations of lumit is known thatthis phenomenon only:

makes use of variations of tension and these variations are applied atthe terminals of a condenser whose'dielectric, when it is liquid.produced electric rotary polarization effects which may be considered asinstantaneous s of the order 4X10-8 seconds according to MM. Abraham etLemoine) upon-an analyzed luminous beam passing through it.

But, by interposing between the receiver and the amplifying systemcomprising a suitable number of stages, tensions as high as desired maybe applied at the last plate to pro duce rotary electric polarization ata suitable point. This tension which is raised but modulated, willtherefore be applied directly or otherwise to the terminals of the Kerrcondenser; a Very powerful and constant luminous beam passing throughthe analyzer to start with will become more or less obscured bypolarization; the rectifier can only reconstitute a light more or lessattenuated.

The condenser will finally impose on the beam graduated properties whichare a function of the variations of resistance of the photo-sensitiveelement at the transmission and therefore a function of the illuminatedobject sighted by the seeing station.

The beam thus obscured may, by any suitable form of condenser, give astationary circular spot of variable brilliancy.

It is this beam which will be subjected to a distribution similar to theexploration I at the seeing post. I

If the spot T be considered as the o'bjectA. B. sighted at the seeingstation the sa'lne optical means (Figure 3) is employed-i. e. lens 0giving a real optical image sent by the mirrors m,'(slower) and m(rapid) turning about a mutually perpendicular axes. Figure' shows anarrangement which is more spaced owing to the divergent lens 0 Finallyand for fairly rapid, movement of 1 b 0 mirrors m,, m an image willappear on the screen-made up of successivelin'es of projection of thebeam emanating from the spot T and which image is illuminatedcorrespondingly with points of the object sighted at the seeing station.

The projection of this image on the large screen may be effected inseveral ways:

(a) Merely by using a lens 0 ofsufficiently large focal distance withoutthe lens 0 (b By adjusting the distances 0,, 0 for biinging to a focusa-suitably sized image 0 T. 4

. (a) By forming an aerial image which will be projected by a lens ofshort focal length and of large aperture.

The establishment of sighting and projecting stations will be easilyunderstood while reconstitution of the image for projection does notoffer any difiiculty provided -mirrors M M and m m move in rigouroussynchronism so that the reconstitution will only be the repetition ofthe exploration. It

is moreover clear that-no means of displace- Y I I ment comprlsmg amechanical member can probably give satisfaction and control movementsof the required rapidity.

Synchronization, however, can be obtained in the following simple mannerThetwo low speed mlr'rors M are formed as'vibratory or oscillograph'galva I nometer mirrors; one oscillation produced at 4. Finally, takingup this beam by a pow the sighting station, of a wave length differentfrom that modulatedby the photo-sensi-v tive element is theremanipulated. This 0s-, cillation will be received by a suitable meansboth at the transmitting and receiving station and will simultaneouslycontrol, in rigorous synchronisin, the mirrorsM 1n,. The mirrors will bethus displaced to the maximum, they will return by reverse effect withidentical and simultaneous movements which may be rendered continuousand uniform in v p jection; 1t 18 only necessaryforthis purpose anysuitable manner.

It may only be necessary for 'the control of these movements to employmechanical means which areas regular and-similar as 'ble; as receptionis effected with a proection which is. always. visible, it will be easyand simple so to regulate, at the moment itself, the s eed of. the meanswhich controls the mirror remain correct without there being any need ofa connection between the .two stations for thiss purpose. counterGuiller chronometers, etc., are very suitable for use.

Whereas in Figure 2', there is no oscillograph at the transmission end,the rapid receiving mirror is adjusted by a wave .emitted at thetransmitting station; b the word adjusted must be understood t eequivalent to i the control of the'transmitting telegraphic type, or acontact disk circuit'breaker or alternator.

It will be understood from the foregoing that the details may vary theinvention however ls characterized by the features:

ll, At the seeing station. 1. Production of a real optical image of theobject seen.

exploring mirror.

2.' Ex ploration of thelimage by a photosensitive element followinglines, combined with a movement of mirrors.

3. Modulation by the photo-sensitive element of a radio electricemission.

4. Emission of another radio electric modulation, manipulated forcontrolling the rapidly explorin mirror.

5. The mec anically controlled low speed II. At the projection station.

2 that the image projected may,

ynchronous motors, clock mechanism,

paratus, means includin erful projecting means.

5. Receiving the-manipulated wave for the control mirror. 6.Mechanically controlled slowly moving distribution mirror whetherdirectly or indirectly placed in accord with the mirror at the seeingstation.

The formation at the receiving station of a real optical image furtherallows the image to be collectedon'a film destined for proof the'quickmoving distribution that the movements of displacement of thereceiving-.film "should be co-ordinated with those of the di'stributingand explorin mirrors invorderithataone image ma exchanged forthei'magefollowing without confusion;

This eo-ordination takes place as can easily be understood owing" to themanipulation which adjusts the mirrors at a high speed and owing tothejmechanism which turns the mirrors at alow speed.

Telecinematography without wires' can therefore be effected.

This operation: moreover allows the d rect cinematography of the movingpro ection of moving images produced at the pro ecting station. In bothcases there will if. mstantaneously and at any distance, thecinematographic film of the movements sighted at the seeingstation, andthis is the. second ob ect of the present invention.

Having now particularly descr bed and ascertained the nature of my saidmvention and in what manner the same is be performed, I declare thatwhat I claim is 1. In an electrical image transmitting apan objective ofshort focal length for pro ecting a luminous image beam, aphotosensitive means of a character for impressing modulations upon acarrier wave, two scanning mirrors oscillating in lanes mutuallyerpendicular to each other or scanning the cam and impressing theresultant luminous points upon the photosensitive means, one of saidmirrors being placed close to and behind the objective so as tointercept and act upon the beam at a point materially short of its fullfocal point, and a second objective of greater focal length than thefirst objective disposed in the path of the deflectedbeam'between thefirst and second mirror. v

2- In an electrical image transmitting u paratus, means including anobjective of short focal length for projecting a luminous image beam, aphotosensitive means of a character for impressing modulations upon acarrier wave, two scanning mirrors oscillating in planes mutuallgperpendicular to each other for seaming th cam and impressing theresultant luminous points upon the photov sensitive means, one of saidmirrors being po- Ill ' paratus, means including an objective of shortfocal length for projecting atrue' image beam, a photosensitive means ofa character for impressing modulations upon a carrier wave, two scanningmlrrors oscillating at relatively high and low speeds in planes mutuallyperpendicular to each other for scanning the beam and impressing theresultant luminous points upon the photosensitive means, one of saidmirrors being; placed close to and behind the objective so as tointercept and act upon the-beam at a point material y short of its fullfocal point, and a second ob- .jective comprising a compound microscopedisposed in the path of the vreflected beam between the first and secondmirror.

In testimony whereof I afiix my signature.

EDOUARDBELIN.

